Envelope construction



Dec. 20, 1938. R HEMPH|LL 2,141,084

ENVELOPE CONSTRUCT I ON Filed July 1, 1936 JOHN DOE X. STREET EAST\\\ f-\BC TOWN Patented Dec .20, 1938 UNITED STATES PATENT OFFICE e,141,os4 ENVELOPE CONSTRUCTION Robert H. Hemphill, Beach, Fla. Application July 1, 1936, Serial No. .ss,4":3

7 Claims. (01.22946) 7 This invention relates to envelopes of that type wherein an opener in the form of a thread, cord or fine wire is placed along and inside of an edge of the envelope so that the latter may i be opened simply by exerting a quick pull onthe thread and slitting the edge.

Envelopes having opening means of this type are convenient and there is a wide demand for the same in the market, but despite the numerl ous attempts as evidenced by the prior art to produce a marketable or commercially practicable job no one has apparently heretofore been successful. The problem is not as simple as would appear at first glance. Envelopes must be produced at a very low cost, and the incorporation of the opening member should not require added manual labor, complex machinery or retard the manufacturing operation. The envelope shouldmeet the requirements of the postal authorities.

there be any unsightly thickened or bulky portions which would be crushed and mutilated by the stamping machine, or scoring or perforations to weaken'the envelope. The edge-cutting thread must be relatively fine and this renders it exceedingly difficult to handle by automatic machinery. If adhesive is applied to'that portion of the thread which is exposed to the contents of the envelope-fit will adhere to the contents and may mutilate the latter during the opening operation. The thread must be located in such position that it will not be caught by, or interfere with the contents of the envelope while the latter is being loaded and sealed.

I have. devised an improved self-opening envelope and method of making same which effectively meets and overcomes the foregoing prob lems. In my method the arrangement is such that the thread may be drawn in a straight line across and at right angles to the path of travel of the envelope blank and held relatively taut while being severed and positioned, and no manual handling of the thread is required to posi-, tion same in the envelope. The thread preferably extends along the bottom edge of the envelope and there is no glue or adhesive on its exposed portion to adhere to the contents of the envelope. The incorporation of the threadadds no material cost to the production of the envelopes. The completed envelope has no weakened portions at the corners or elsewhere, there are no projections or thickened portions, and in fact the envelope is substantially similar in every way to the ordinary envelope except that There should be no projecting parts at the corv ner or elsewhere to catch and tear nor should.

I prefer to use an indicating mark for the tearing portion. I

The various features of novelty. and advantage of my improved envelope and method of manufacture will become more apparent in viewof the following description taken in conjunction with the drawing, wherein, I

Fig. 1 is a view inplan of an envelope blank preparatory to receivingthe. thread;

Fig. 2 shows the thread length cut and in place in theblank;

Fig. 3 shows the succeeding folding operation; Fig. 4 shows the completed envelope. v A blank is first cut substantially as shownjin Fig. l with a body 5, opposed side or end flaps I 6 and 6a, a bottom flap 1 and sealing flap 8.

Preferably simultaneously with the blank-cutting operation, tabsv or ears 9 and 9a are formed at the opposite edges of the blank at the junc ture of the bottom fiap 1 with the side or end flaps 6 and 6a.,- These tabs or earsare preferably formed on the flaps 6 and Baby the blankcutting die, not shown in the drawing but construction of which is well understood in the art.

An adhesive may then be applied along the marginal edges of the bottom flap 1 and to the tabs 9 and 9a,

A thread 10 is stretched over the pathof travel of the blank, and as the foldingline ll,

registers with the thread, the tabs 9 are folded over the thread against the surfaces of the flaps 6 and 6a and sealed, catching and holding the thread ends. The thread may be severed before, after or during its positioning in the blank, de-

pending upon the design of the thread handling mechanism. In one design, the thread is gripped at spaced points, severed and then lowered into registration with the line H and tabs 9, the tabs then folded and the thread length released, while in another design the thread is severed after the l 40 folding materially simplifies the automatic placement of the thread lengths.

The next step is shown in Fig. 3, the fiaps 6 and to being folded over carrying the tabs 9 and 9a and thread ends therewith turning the thread ends back re-entrantly and securely holding the same in place." It will be noted that no surface having glue or adhesive thereon is exposed to the interior of the envelope.- Another important feature is that the folding" back" of the flaps, G and 6a with thetabs thereon in effect locks the thread ends in place sothat the adhesive is not 1 solely depended on'for this function, and this 5" locking action follows in the normal manufacture of the envelope.

Finally, the bottom flap 1- is romeo over and may be adopted or this feature may be omitted if desired.

The handling of the thread and folding of the tabs! and 9a may be done'by automatic machinery, and while I have not shown any preferred type of mechanism for accomplishing this purpose, yet it will be understood that suitable mechanism may be adopted by those skilled in the art. Sincethe thread is placed'along the bottom edgeof thevenvelope, it will be out of the way of the contentsof the same when inserted imtheerivelope. There are no glued surfaces exposed'to the contents of the envelope either on the thread or the tabs for holding the thread.

The strength of the envelope remains unimpaired since there are no apertures or weakened surfaces caused by perforations or scoring. Further there are no bulges such as would be formed by knots nor are there any projecting ears or tabs at the corners which would catch and tear during handling in the mails. I have found that this type of self-opening arrangement may be embodied in the usual envelope making machinery simply by the addition of mechanical thread positioning and severing mechanism and tab folding mechanism of relatively simple construction.

The opening operation is simple and well understood, 'it being only necessary to tear off one of the bottom corners of the envelope and give.

the thread a relatively sharp pull at approximately a right angle to the bottom edge of the envelope.

It will be understood that certain minor changes in the steps of the method and in the structure andarrangement of the thread-holding tabsmay be adopted within the scope of the invention as deflnedby the appended claims.

I claim: i

1. In the manufacture of envelopes, the step which consists in forming thread-holding tabs in the marginal edge of an envelope blank at the opposite ends of the line of fold of a folding g flap, holding a thread free of adhesive over and in substantial registration with said line of fold and said tabs and folding the latter over to hold the thread, and thereafter folding the tabs and thread ends back over the body of the blank.

2. The method of making an envelope of that type having an opening thread underlying an edge thereof, which consists in first forming a blank with a body portion and opposed side and bot- .tom folding flaps and thread-retaining tabs or ears in the marginal edges of the blank at the juncture "of the side flaps with the bottom flap, holding a thread, length in a non-slack condi tion over the line of fold of the bottom flap and folding-the tabs over the thread and securing them against the end flaps, then folding the end flaps and tabs over the body and finally folding the bottom flap over and securing it to the end flaps.

3 The method of making an envelope of that type'having an opening thread underlying an edge thereof, which consists in first forming a blank with a body portion and opposed side and bottom folding flaps and simultaneously forming thread-retaining tabs -or ears in the marginal edges of-the blank at the juncture of the end flaps with the bottom flap, applying an adhesive to the marginal edge of the bottom flap and also to the tabs, holding a thread length relatively taut over the line of fold of the bottom flap and folding the tabs over the thread and against the end flaps, then folding the end flaps and tabs over the body and finally folding the bottom flap over and securing it to the end flaps.

v 4. The method of making an envelope of that type having an opening thread underlying an edge thereof, which consists in first forming a blank with a body portion and opposed side and bottom folding flaps with thread-retaining tabs or ears on the side flaps adjacent the opposite ends of the line of fold of the bottom flap, applying an adhesive to said bottom flap and also to the tabs on each end flap and holding a thread length relatively taut overand in substantial registration with the said line of fold and tabs or ears and folding the tabs orears over against and securing them to the inner surfaces of the side flaps, then folding the side flaps over the body portion and finally folding the bottom flap over and securing it to the end flaps.

5. An envelope having a body portion with folding'flaps at opposite sides thereof and a bottom in the bottom edge thereof with its opposite ends caught by tabs which are formed on the side flaps and turned inwardly and secured to the inner surface of the latter, said thread being free a of adhesive between its caught ends and the corner's of'the envelope being u'nweakened and free of projections. I

'7. An envelope having a .body portion and a pair of oppositely disposed fiaps which are folded inwardly over the body portion, another flap folded at substantially a. right angle to the firstnamed flaps and overlapping and secured to said first-named flaps, an edge-slitting thread extending along the line of fold of the overlapping flap, thread holding f. bs or ears located adjacent the ends of the line of fold of the overlapping flap and turned inwardly over the opposite ends of the thread against the inner surfabes of the oppositely disposed flaps, said thread ends and tabs being turned inwardly over the body portion and the thread ends substantially locked in position due to the folding of the oppositely disposed flaps. H Y ROBERT H. HEMPI-ECLL. 

